At the end of March 2008, the Duchy of Lancaster had £399m of net assets under its control. These take the form of property and financial assets. The property assets can be divided into rural estates, urban estates and development land.

The following pie charts show how the asset mix has changed since March 1999:

Asset Mix Capital - March 1999 Capital - March 2008

The growth in net assets over the last ten years, split by category, can be seen from the graph below:

Growth in Net Assets 1999-2008

The graph demonstrates the strong growth in net assets over the last ten years. However, as some categories grow faster than others, the overall ratio of one asset class to another starts to vary over time.

The officers of the Duchy manage its property and investments.
The net revenues from the property and investments are paid to the Keeper of the Privy Purse, the member of the Royal Household who is responsible for managing the Sovereign's finances. Revenues presented to the Sovereign are currently in the region of £12.5m per year.

The Duchy of Lancaster is a long-term capital asset of the Crown. The Sovereign is not entitled to the Duchy's capital, nor to capital profits. Revenue generation is balanced against the long term need to provide income for future generations of Sovereigns.
 
The Crown Lands Act of 1702 placed an absolute bar on the alienation of Duchy assets, and restricted the Sovereign to the receipt of income generated by these assets. Later legislation has made this more flexible. Subject to the Duchy of Lancaster Lands Act 1855 and the Duchy of Lancaster Act 1988, land may now be bought and sold and long leases granted. Sales of assets only take place where judged appropriate, and core estates are not affected.

The financial affairs of the Duchy are governed by legislation. The Duchy of Lancaster Lands Act 1855 governs capital transactions for the sale and purchase of land, whilst the Duchy of Lancaster Act 1817 (known as Viscount Gage's Act) deals with investment in the improvement of land already owned by the Duchy. Investment in financial assets is governed by the Trustee Act 2000.

The Duchy of Lancaster does not pay tax, but the income receivable by the Privy Purse (of which the Duchy's contribution forms part) is taxable, after the deduction of official expenditure.